356.30 Securing and Supporting.
Type LFNC-B shall be securely fastened and supported in accordance with one of the following:
(1) Where installed in lengths exceeding 1.8 m (6 ft), the conduit shall be securely fastened at intervals not exceeding 900 mm (3 ft) and within 300 mm (12 in.) on each side of every outlet box, junction box, cabinet, or fitting.